In the use of precision weapons, e.g. in the use of rifles or handguns for wing or target shooting competitions, oft-times a remarkable training of the shooter is required in order to limit the effects of the deviation on bullet trajectory imposed by weapon movement at bullet ejection.
Such a movement, also known as recoil effect of firearms, is caused by gunpowder combustion gases which, by being able to expand only horizontally inside the firearm barrel, push the bullet toward the muzzle and the breech, and therefore the weapon itself, in the opposite direction.
Therefore, the effect of the recoil phenomenon influences the shooter's aim since the weapon moves at the same shooter's hand or shoulder.
In the state of the art there are numerous shock absorber devices for reducing the recoil of a firearm.
Document US2010/0122482, e.g., describes a recoil reducer device for firearm, device which is positioned inside two cavities, aligned therebetween, obtained respectively in a distal portion and in a proximal portion of the shoulder stock of a firearm.
The device comprises a shock absorber system comprised of a plurality of members, such as a piston, a spring, a magnetic element and iron plates, which overall enable the device to be moved between the rest position and the recoil position.
The change of position is carried out by means of a relative sliding of the sole proximal portion on the distal portion of the shoulder stock, and the magnetic element positioned inside the described device acts as return member, for the device itself, from the recoil position to the rest position.
A further anti-recoil device for firearms, substantially having a firing damping function, is described in WO2008/030128.
Also in document U.S. Pat. No. 3,208,179 a shock absorbing device for absorbing the shock of a firearm is described, comprising a coil spring, two pushing elements and two cams.
A drawback of known devices is that they have a remarkable encumbrance, oft-times requiring precision machining on the weapon which increase its production costs.
Moreover, those are devices which only partially reduce the phenomenon of deviation of bullet trajectory at ejection of the bullet itself from the firearm.
The above-mentioned devices are unable to oppose the thrust which barrel-contained gases exert on the bullet before the latter exits the barrel, thrust causing bullet deviations from the set direction of shooting.
Besides the impact on the shooter's grip, the recoil has an effect also on the positioning of the end portion of the barrel.
At the exiting of the bullet from the barrel, part of the energy due to recoil causes a rotation of the weapon about the bearing or grip point of the weapon itself, causing a climb of the muzzle.
Obviously this effect, also called bounce, depends on numerous characteristics, and is variable with the bullet speed and weight, the barrel length, the specific shape of the weapon, the weapon weight, the relative position of the grip with respect to the barrel, and with the same mode with which the weapon is gripped by the shooter.
Systems for reducing said phenomenon exist; e.g., there are rifles provided with a plurality of holes on the barrel surface, so as to cause a certain amount of gases to be conveyed therein to at least partially compensate for the phenomenon. The effectiveness of such a system is partial, and is anyhow linked to the size, number and specific positioning of the holes made on the barrel surface.